Brendon Hartley posted a 3m26.013s with around 50 minutes of the opening three-hour first practice session remaining in the #8 Toyota GR010 HYBRID - a time that is almost a second faster than Porsche managed at last Sunday's Test Day. Callum Ilott's 3m26.
610s in the #12 Jota-run privateer Porsche 963 LMDh had topped the timesheets for much of the session, before the Briton was relegated to second. BMW M Hybrid V8 LMDh pilot Dries Vanthoor had briefly assumed second place with an effort in the closing minutes, but this was later deleted for a track-limits breach. But his subsequent 3m26.
671s was still good enough for third spot, ahead of the customer Proton 963 of Julien Andlauer - another late improver. Nyck de Vries' 3m26.918s in the opening minutes ensured that Toyota had two cars in the top five.
Also within a second of Hartley's benchmark was the #2 Cadillac V-Series.R LMDh of Alex Lynn, who posted a 3m26.928s early on.
However, Lynn later caused one of two red flags when he crashed into the barriers at Terte Rouge with around 20 minutes of FP1 remaining. Next up in seventh spot was the second of the two BMWs, courtesy of Robin Frijns. Ferrari's defence of its Le Mans victory last year began in low-key fashion with the fastest of the trio of AF Corse-run 499Ps in eighth place with Antonio Fuoco in the #50 machine also just under a second off Hartley's time.
The two Alpine A424 LMDhs, on their maiden Le Mans outing, rounded out the top 10, while the best of the Peugeot 9X8.